Hello, I’ve resorted to this forum in hopes I can find what is wrong with my truck. I have a persistent tap or knock coming from what sounds like the front of my engine, I’ve described the issue to my diesel mechanic who told me it was a bad crank pulley, he is the only person who has worked on this truck, is a very trusted man in my community and has experience with the 6.5 as he daily’s one. Hopefully I can attach the video and hopefully you guys can help. The sound responds to engine RPM and continues for a brief second after the engine turns off. It also was very slight after the truck had been sitting for a while but then became louder. Thanks!